Muntin grids consist of lineal elements that are destined to subdivide an opening created by a perimeter frame work assembly, particularly in the context of windows and doors. Such assemblies are usually referred to as divided lights.
As it is known in the art, said muntin grids traditionally formed a structural assembly with the perimeter framework, creating a multitude of openings that had to be closed by a multitude of smaller panes of glass. Surface-applied muntin grids within a perimeter framework, however, provide the advantage of using only a single glazing element to close the opening. In the case of a glazing element made from more than one pane of glazing, such as an insulating glass unit, an additional muntin grid can be installed internally in-between the panes, to create a likeness to the traditional divided lights.
In the context of windows and doors, the said perimeter framework, which retains the glazing, is called either a sash frame or a main frame, depending on its intended function. Sashes are typically mobile elements within a main frame which retain the glazing and hold the necessary working hardware to allow them to slide, pivot, tilt, lock, etc. for ventilation, egress and cleaning purposes. In the context of doors, the mobile element consisting of the perimeter frame and the glazing is usually referred to as a panel.
In the case of fixed glazing assemblies, the perimeter frame, which retains the glazing, is called the main frame. Such products are referred to either as fixed windows or as door side-lights.
Muntin grids are intersecting bar assemblies that are installed in aligned and parallel relationship with the plain of the glazing for the purpose of creating the appearance of individual, divided lights.
In the manufacture of a muntin grid assembly, one typically starts with lineal profiles. These profiles are designed to incorporate specific functional features related to the assembly and mounting processes and to display a certain traditional look.
Furthermore, although many materials of construction are conventionally utilized for the manufacturing of muntins, such as wood, thermoplastics and aluminum, this invention emphasizes the use of fiber-reinforced, duroplastic lineals, such as pultrusions, because of their superior stiffness, their low thermal expansion and contraction rate and their excellent corrosion resistance.
Muntin grids are commonly made of profiles that intersect at right angles, creating rectangular openings. However, muntin grid profiles can be designed to intersect at angles other than 90°, producing a diamond-shape grid pattern.
Fabrication of muntin grid assemblies are done in several different ways. The grids may be assembled by the use of individual muntin bars, the lengths of which correspond to the respective length of each side of the opening that they create. This method results in a structurally weaker assembly making it difficult to align the grid with its intended pattern. Stronger grids are assembled using continuous profiles in both directions. At intersections, bars are being notched or pierced to interlock with each other in an overlapping or penetrating fashion. U.S. Pat. No. 4,060,950, to Rackard et al.; U.S. Pat. No. 4,652,472 to Davies; U.S. Pat. No. 4,989,384 to Kinghorn et al. and U.S. Pat. No. 6,425,221 to Reichert are representative of these types of assemblies. However, this method is only practical when the grid profile is of a rectangular, cross-sectional box shape.
The assembly method preferred in this invention is the use of continuous muntin bars in one direction and short, individual lengths of muntin bars in the other direction. This method provides the grid with ample stiffness, while still allowing for the use of decorative, complex muntin bar profile shapes to be mated at the intersections. As it is known in the art, and described in U.S. Pat. No. 4,437,284 to Cribben et al.; U.S. Pat. No. 4,970,840 to Ouellette and U.S. Pat. No. 6,244,012 to McGlinchy, this type of mating depends on reliable connection methods for the purpose of attaching the short muntin bars to the continuous ones which require precise and complex machining of the mating portions of said muntin bars. The invention provides substantial simplification of the fabrication of such intersections with the provision of a uniquely structured intersection clip.
To achieve this simplification the invention discloses use of a spring-type clip arrangement for connecting together the continuous and the intersecting short muntin bars. A spring clip is designed to lock its central portion through snap-engagement to the continuous muntin profile. The clip extends arms beyond the continuous bar on opposite sides. Each extension arm serves as a spring-type clip for snap-engagement with the mating shorter muntin bars.
For the purpose of creating the intersection, this method eliminates the need for any machining of the continuous muntin bars and it limits the preparation of the short muntin bars to the machining of their mating interfaces.
Muntin grids can be mounted as removable elements or as permanently attached assemblies. Removable grids commonly are snap-fitted to the perimeter frame as disclosed in U.S. Pat. No. 4,644,721 to Bloomquist et al.; U.S. Pat. No. 5,437,133 to Pliml and U.S. Pat. No. 6,230,456 to Merchlewitz. Alternatively, they are equipped with attachment means to be retained within the perimeter frame as disclosed in U.S. Pat. Nos. 4,970,840 to Ouellette, and U.S. Pat. No. 5,048,252 to Osborn.
Permanent grids, which are positioned within the space between glass panes of a sealed glazing unit, usually are mechanically attached to the spacer bar along the perimeter by the use of pins or clips as described in U.S. Pat. No. 6,131,356, Gieseke and U.S. Pat. No. 6,425,221 to Reichert. External permanent grids are most often mechanically attached to the perimeter frame as disclosed in U.S. Pat. No. 4,644,721 to Bloomquist et al.; U.S. Pat. No. 5,437,133, Pliml and U.S. Pat. No. 6,230,456 to Merchlewitz and may be integral with said perimeter frame as described in U.S. Pat. No. 5,331,727 to Golen. Commonly, the muntin bars are bonded to the adjacent glass surface for permanent retention.
As it is known in the art and described in U.S. Pat. No. 4,989,384 to Kinghorn et al. and U.S. Pat. No. 5,291,710 to Golen, muntin grid assemblies can be provided with a continuous outer border profile that closes the perimeter openings and described in. It provides greater stiffness and eases alignment of the muntin bars. However, the width of the outer border projects into the glazing area and reduces the vision area of a window or door. Therefore, it is more desirable to make the outer perimeter of the grid pattern open, leaving the ends of the muntin bars unsupported.
Another aspect of the present invention relates to the attachment of the free ends of the muntin grid assembly. Under currently known methods the proper alignment of said free ends is difficult. This difficulty increases when exterior and interior muntin grids are being used in combination to achieve more likeness with true divided lights. The aesthetics of muntin grids can be enhanced further by the addition of an internal grid, positioned in between the glass panes of a sealed glazing unit as disclosed in U.S. Pat. No. 5,345,743 to Baier and U.S. Pat. No. 6,425,221 to Reichert. The use of exterior, interior and internal muntin grids in combination amplifies the problem of grid alignment.
The essence of this aspect of the invention is the creation of a means for the attachment and the alignment of muntin bar free ends of multiple grid assemblies used in combination. As it is known in the art, free muntin bar ends can be attached individually to a perimeter frame by mechanical means, such as fasteners, pins and clips. Said means are exclusively designed to serve for the attachment of a singular grid assembly only. Representative patents include U.S. Pat. No. 3,108,336 to Tate; U.S. Pat. No. 4,437,284 to Cribben; U.S. Pat. No. 4,644,721 to Bloomquist et al.; U.S. Pat. No. 4,970,840 to Ouellette; U.S. Pat. No. 5,048,252 to Osborn; U.S. Pat. No. 5,437,133 to Pliml; U.S. Pat. No. 6,131,356 to Gieseke; U.S. Pat. No. 6,230,456 to Merchlewitz and U.S. Pat. No. 6,425,221 to Reichert.
The invention provides a uniquely structured end clip for the attachment and alignment of a plurality of muntin grids in combination. The end clip includes an attachment means that consists of a snap-type clip arrangement that overlaps the glazing edges for the purpose of aligning and retaining the free ends of the respective muntin grid assemblies. The clip consists of a “U”-shaped central portion which is destined to straddle the edge of the glazing. The end-portions of the clips project beyond the engagement of the glazing edge within the sash frame, or within the main frame, thus presenting aligned attachment means to the free ends of the muntin grids at both, the outer and the inner faces of the glazing. Furthermore, when aligning said perimeter clips with the ends of the additional, internal grids, this will ensure the perfect correspondence of all muntin grid assemblies.
Use of adhesive means for the bonding of muntin grids directly or indirectly to glazing surfaces has been described in U.S. Pat. No. 5,345,743 to Baier or U.S. Pat. No. 4,437,284, Cribben et al., respectively. This can be achieved through various materials, i.e. liquid adhesives or dry adhesive tapes. Double-adhesive, pressure sensitive tapes are the most commonly used materials. The use of double-adhesive tape, in combination with the end clip snap-type arrangements for the purpose of enhancement of the retention of the muntin grid assembly within a sash-frame or main frame, represents a further advancement of the preferred assembly method. However, it is important to understand that by overlapping the junctions of the grid profiles with an application of the double-adhesive tape, covering the mating, short profiles from one side of the grid to the other, the whole grid assembly becomes more rigid and easier to manipulate during the application process, thus greatly assisting with the alignment of the grids.
It is a broad object of the present invention to provide a muntin grid assembly and a means of mounting said muntin grid into a frame work assembly that can overcome the prior art deficiencies and shortcomings.
It is another object of the present invention to provide a muntin grid assembly and a means of mounting said muntin grid into a frame work assembly in a simple, yet reliable manner with a minimal effort and low manufacturing costs.
It is a specific object of the present invention to provide a uniquely structured intersection clip having a spring-type arrangement for connecting together continuous and intersecting short muntin bars.
It is another specific object of the present invention to provide a uniquely structured end clip having a snap-type arrangement for attachment and alignment of a plurality of muntin grids in combination. The snap-type arrangement overlaps the glazing edges for the purpose of aligning and retaining the free ends of the respective muntin grid assemblies.